Variable valve mechanisms are described in Patent Documents 1 to 5. As with a variable valve mechanism 100 according to the related art (Patent Document 5) illustrated in FIG. 8, for example, all of the variable valve mechanisms include a rocker arm 101 that is swingably supported by a single pivot 105 and that swings when pressed by cams 108 and 109 to drive a valve 6, and a switching device 106 that operates the rocker arm 101 to switch the drive state of the valve 6.
Specifically, the rocker arm 101 includes an inner arm 103 and an outer arm 104 provided around the inner arm 103. The inner arm 103 is pressed by an inner cam 108. The outer arm 104 is pressed by two outer cams 109 and 109 having the same profile and provided on both sides of the inner cam 108 in the width direction. The switching device 106 relatively indisplaceably couples and decouples the outer arm 104 to and from the inner arm 103 to switch the drive state of the valve 6.